Diagnostic System Check. Chevrolet PJJ 2000

For 1990-2009 cars

### Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

1. Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.

2. The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.

3. DTC B1000 and DTC B1001 are internal BCM malfunctions and should be corrected before performing any other diagnostic procedure.

4. DTC B1328 sets when battery voltage is above 18.5 volts and should be corrected before performing any other diagnostic procedure.

Step | Action | Yes | No
--- | --- | --- | ---
1 | Install a scan tool. Does the scan tool power up? | Go to Step 2 | Go to Scan Tool Does Not Power Up in Data Link Communications

2

1. Turn ON the ignition, with the engine OFF.
2. Attempt to establish communication with the body control module.

Does the scan tool communicate with the body control module?

Go to Step 3

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

3 | Select the body control module display DTCs function on the scan tool. Does the scan tool display any DTCs? | Go to Step 4 | Go to an applicable symptom table
4 | Does the scan tool display any DTCs which begin with a "U"? | Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications | Go to Step 5
5 | Does the scan tool display DTC B1000 or B1001? | Go to Diagnostic Trouble Code (DTC) List/Type in Body Control System | Go to Step 6
6 | Does the scan tool display DTC B1328? | Go to Diagnostic Trouble Code (DTC) List/Type in Engine Electrical | Go to Diagnostic Trouble Code (DTC) List/Type